Floor sander



Filed Nov. 25, 1955 Patented Dec. 14, 1937 FLooR. SANDER Y Fred VL. Detwiler, Santa Ana,10alif. Applimtion November 25, 1935, serial No.V 51,418-

1 claim. (o1. 51-175i My invention relates to a 4floor sanding machine of the type where two ormore blocks or plates are mounted side by side for reciprocatory movement and the underfaces of which plates or blocks are coveredwith sandpaper or the like.

The `principalobjects of my. invention are, to generally improve upon and simplify the construction of the existing forms of similar floor Sanders andV to provide a sanding machineof l0 relatively simple, durableconstruction which may be` manufactured atcomparatively low cost and which will be economical in operation and very effective in use.` Y

Further objects of my invention are, to provide alsandlng machine of the character referred to that includes a wheel supported carriage thatisY adapted to be moved over a floor by means of a handle, said carriage carrying an electric motor' for driving the reciprocating plates that are provided on thfeir'underfaces 'with sandpaper; further, to provide relatively simple, strong and'durable'means for supporting and guiding the plates during their reciprocatory movement and further, to Vprovide-simple and efficient means for clamping the sheets of sandpaper or the like to the ends vof the reciprocating'plates.v A further object of my invention is, to provide a floor sander that may be conveniently employed for'sanding all portions of a floor, particularlythe ooring in the corners of a vroom or along Athe edges immediately adjacent the base boards, thereby eliminating the necessity of hand labor on those portions of the floor in the'corners or `adjacent the wall or base board. Y D Withthe foregoingand other objects in view my invention consists in certain novell features of construction and arrangements of partsrthat will be v4hereinafter more fully describedand claimed and illustrated in the accompanying drawing in which: l

Fig. lisa side elevational view of a floor sander constructedin accordance with my invention.

Fig: 2 isa top plan view.

Fig. 3 is a front elevational View.

Fig. 4 is a vertical cross section taken on the line 4 4 of Fig. 1.

Fig. 5 is a vertical cross section taken on the line 5--5 of Fig. 1; and

Fig. 6 is a detail vertical section taken on the line 6-6 of Fig. 2.

Referring by numerals tothe accompanying drawing which illustrates a preferred embodiment of my invention, IB designates a bed plate and projecting upwardly and rearwardly from the rear end thereof, is a handle I I, by means of which .the machine isumovedover theoor that is being sanded. Plate I0 supports an electric motor I2, that is equipped with a cord and plug for supplying current to said motor.

Rigidly secured to the underside of the for- 5 r;

ward portion of plate I0, is a plate I3 .and projecting forwardly from the sidesthereof, are parallel arms I4.

Depending from the sides of plate I3, are bear- `ings |55 for anfaxle I6, on which are mounted 10e small wheels I'l,` preferably provided with rubber tires. Projecting upwardly from vthe arms I4 directly in front of plate I3, are bearings I8 for a transversely disposedfcrankshaft -I9,1 which latter* in 15.1'.l

the present instance, is provided with two oppositely arrangedcranks 20. Y

Secured on one end of the crank shaft I9, is a belt wheel 2l and abelt 22 connects said 'belt wheel `with .a small pulley 23- that is mounted on 20 the shaft of motorV I2.

Projecting from theouter ends of the bearings I8 and surrounding the shaft journaledV therein, are lugs or bushings 24, on which are loosely mounted the rear ends of forwardly pro- 2 5E jecting` parallel arms r25.

Ifile-forward' ends of these arms terminate above the endsfof the arms I4 and said forward ends are pivotallymounted on trunnions 26 lthat project from the sides of vertically disposed sub- 30` stantially H-shaped frame 21.

The lower ends of the vertical legs of this frame rest on a transversely disposed rod 28 that connects the forward ends of the arms I4.

Asecond vertically disposed'substantially H- 35V shaped frame 29 is arranged between the rear portions of the arms 25 a short distance in front of the crank shaft I Sand trunnions 30 project from the sidesof said frame 29 through said arms 25. 40.

Seated in the "upper and lower ends of the ver-Y ticallegsof the frames `2'I vand 29, are'longitudinallydisposedparallelrods- 3|;V

The arms 25, the upright frames 21 and 29 and the rods 3| constitute a skeleton frame for the 45 reciprocating plate carrying members hereinafter more fully described and as the rear ends of the arms 25 are journaled on the bushings 24, the entire frame may be readily swung upward with respect to the arms I4 when the sandpaper car- 50 rying plates are detached from the supporting and reciprocating means.

The ends of the legs of a pair of substantially X-shaped members 32 are provided with bearings 33 that are mounted for sliding movement upon 55 the rods 3| and pivotally connected to the central portion of each X-shaped member is the forward end of a connecting rod 34. The rear ends of these connecting rods are journaled on the respective cranks 20 of crank shaft I9.

For the accommodation of the connecting rods 34, the vertical members of the H-shaped frame 29 are provided with vertically disposed slots 35.

Depending from the lowermost one of the bearings 33 on each member 32, is a lug 3B and each lug is arrangedbetween and pivotally connected to a pair of ears 31 that are formed integral with and which project upwardly from a plate or head 38.

These plates which are substantially rectangular in shape, occupy positions side by side below the forward portions of arms I4 and the overall width of the two plates is slightly rgreater than the over-all width of the forward portion of the supporting structure.

Formed integral with and projecting upwardly from the ends of each vplate 38, are transversely disposed ribs or flanges39 that are curved inwardly toward the center of the plate, thus providing transverse pockets for the reception of the ends of the sections of sandpaper that are applied to the plate and for the rods that clamp the ends of the sandpaper to the plate.

The means employed for clamping the ends of the sandpaper to the plate includes a pair of toggle structures, each comprising a short curved lever 4|] that is fulcrumed between the ends of the upwardlyprojecting ears 31 andY projecting outwardly from the end of the lever that is fulcrumed to the ears, is a short arm 4I. Pivotally connected to this arm, is the inward end of the outwardly projecting rod,42 and carried by the outer end of this rodis a transversely disposed rod 43 that is adapted` to enter the recess or groove in the corresponding flange 39 and clamp the overturned ,end of the sandpaper. Y Y

When the sander is equipped for use-a section S of sandpaper is applied to the underface ofl each plate 38 vwith the ends of saidvsandpaper overlying the curved flanges 39 and extending downwardly into the pockets or channels therein and by properV manipulation of the toggle members comprising the levers 4D, rods 42 and rods 43, vthe ends of the sandpaper are firmly clamped in the grooves in flanges 39 between rods 43 that are moved outwardly as the levers 40 are swung downward onto the rods 42.

In the use of my improved floor sander, handle II is manually engaged and the entire machine is moved over the floor.

Motor I2 through pulleys 23, 2| and belt-22 impart rotary motion to the crank shaft I9 and the connecting rods 34 that are connected to cranks 26 impart reciprocatory movement to the X-shaped frames 32.V These frames reciprocate lengthwise upon the supporting rods 3l andthus the plates 38 are simultaneously reciprocated.

Due to the arrangement of the cranks 20 on the crank shaft, one plate will move frowardly while the other plate is moving rearwardly.

During operation of the machine, the handle I I is slightly elevated so as to move the forward ends of arms I4 downwardly a short distance so that rod 28 leaves the lower ends of the vertical members of frame 21 and under such conditions the entire weight of the supporting and guiding means including the arms 25, frames 21 and 29, rods 3| and frames 32 is transmitted to the plates 38 so that the same exert considerable pressure upon the floor during the sanding operation.

When the machine is moved from one room to another or from one part of the room to Y another, the handle II is moved downwardly to swing the forward ends of arms I4 upwardly, thereby lifting the plates 38 off the floor.

When it becomes necessary to replace the sheets of sandpaper on the underfaces of the plates 38, the pins that connect the lugs 36 to ears 31 are removed and the toggles that clamp the ends of the sandpaper to the plates are released by swinging levers 40 upward.

Inasmuch as the reciprocating sandpaper carrying plates are slightly wider than the forward portion of the supporting structure of the machine and the forward portions of said plates project beyond the forward ends of the arms- I4, the machine may be conveniently manipu- 5 lated so as to engage all portions of the surface of the floor and particularly at the corners of the room and in the corners between the floor and walls or base board.

Thus it will be seen that I have provided a scribed without departing from the spirit of the invention, the scope of which is set forth in the appended claim.

I claim as my invention:

In a door sander, a wheel supported carriage, a handle projecting from the rear end of said carriage, a pair of arms projecting forwardly from said carriage, a rail connecting the forward ends of said arms, a frame hinged to said carriage and positioned above said arms, the forward end of which frame normally rests on the rail that connects the forward ends of said arms, members mounted for reciprocatory movement in said frame, means onthe carriage for imparting reciprocatory movement to said members, plates pivotally suspended from said reciprocating members and means on said plates for clamping sheets of sandpaper thereto.

FRED L. DETWILER. 

